Several magic-angle-spinning NMR probes are being constructed. These are designed to permit high power (>1 kW) irradiation at several (up to six) frequencies in a single experiment, while maintaining the radio-frequency isolation (>40-50 dB) necessary to observe weak NMR signals (<<1 mW). The design is an optimized transmission line approach, which exploits partial local tuning with shunt capacitors along the transmission line to maximize efficiency on observe channels while maintaining adequate efficiency on decoupling channels to reach the desired RF field strengths (>100 kHz) for high power decoupling experiments. These probes are crucial for performing heteronuclear recoupling experiments such as REDOR and FDR, as well as polarization transfer experiments such as RFDRCP. Probes have been constructed for the 200 and 400 MHz spectrometers, and probes currently in production include 317, 500, and 750 MHz models.